ttT

TTT is an acronym that refers to several different concepts across fields. There is no single universal meaning, but two uses are particularly common: in materials science, where TTT denotes Time-Temperature-Transformation diagrams; and in games, where TTT stands for Tic-tac-toe (also called noughts and crosses).

Time-Temperature-Transformation diagrams describe how the microstructure of steel changes with time at constant temperatures. In a TTT diagram, temperature is plotted against time and curves indicate when transformations such as pearlite, bainite, or martensite begin and finish. They are used to predict final microstructure and mechanical properties after heat treatment and to guide process design. Interpreting a TTT diagram involves locating the curves for the alloy of interest and reading whether a given temperature will produce transformation within a practical time window.

Tic-tac-toe is a simple two-player game on a 3x3 grid. Players alternate placing Xs and Os, aiming to form a straight line of three. If all spaces fill without a winner, the game ends in a draw. Tic-tac-toe is a solved game: with optimal play from both sides, the result is always a draw; the first player cannot force a win. The game is widely used in computer science to illustrate basic search algorithms such as minimax, and there are about 255,168 distinct legal game sequences when all possibilities are counted.